Internal combustion engine



1 3 H. c. EDWARDS 1,891,322

INTERNAL COMBUSTION ENGINE Filed Nov. 25, 1929 2 Sheets-Sheet l gwue/ntoz HERBERT C EUNHRDS Dec. 20, H DS 1,891,322

INTERNAL COMBUSTION ENGINE Filed Nov. 25, 1929 2 Sheets-Sheet Z w I I I A /Z/ 7 T 60 5a 0a toe HERBERT L3 Emzanus Patented Dec. 20, 1932 UNITED STATES PATENT OFFICE HERBERT C. EDWARDS, OF DETROIT, MICHIGAN, ASSIGNOR TO PACKARD MOTOB CAR- COMPANY, OF DETROIT; MICHIGAN, A CORPORATION OF MICHIGAN INTERNAL COMBUSTION ENGINE Application filed November 25, 1929. Serial No. 409,529.

This invention relates to internal combustion engines and more particularly to compression ratio regulating mechanism.

An object ofmy invention is to provide an internal combustion engine having mechanism associated therewith and automatically actuated by the pressure lubricating system to vary the compression ratio inversely to the engine operating speed.

Another object of the invention is to provide a radial Diesel type of engine with an eccentric bearing intermediate the crank shaft and the master rod which is varied in its position by the lubricating system to regulate the compression ratio.

A further object of the invention is to employ the pressure lubricating system of an in ternal combustion engine for actuating compression ratio regulating mechanism, the application of which is controlled by a valve member actuated by centrifugal force.

Still another object of the invention is to provide compression ratio regulating mechanism for a Diesel type ofengine which is actuated by the engine lubricating system inversely to the engine speed so that the compression ratio is lowest when idling to promote ease in starting of the engine.

Another object of the invention is to associate compression ratio changing mechanism with a crank check of the crank shaft in a manner such that the lubricating system is utilized for controlling the position of an eccentric bearing arranged between the crank pin and the connecting rod.

These and other objects of the invention will appear from the following description taken in connection with the drawings, which form a part of this specification, and in which:

Fig. 1 is a rear elevational'view of an engine having a portion of the crank case and a portion of the cylinders broken away to illustrate the compression ratio regulating mechanism and the interior of the cyl-v inders i a Fig. 2 is a side elevation of the forepart of an alrship being partially broken away to illustrate the lubricating system and the compression ratio regulating mechanism Fig. 3 is a sectional view taken on line 33 of Fig. 1, showing the compression ratio mechanism associated with a check of the crank shaft. A

' Referring now to the drawings, 10 designates-thecrank case of. an internal combustion engine which is employed as the source of motive power for'an airship. The interror of the crank case is divided into a plurality of compartments 11, 12, and 13, by the partitions 14 and 15. Thecompartment 11 provides a reservoir for lubricating oil an for housing the pump mechanism for forcng the lubricating oil to the bearings re uirmg lubrication and for-withdrawing oil rom the compartment 12 adjacent thereto. The

compartment 12 is arranged to contain a port10n of the cylinders 16 andthe connecting rod structure and the crank-throw, while the compartment 13 is adapted to contain mechanism (not shown) operated from the cranllg shaft 17 for-actuating the valve mechanis controlling the inlet and outlet ports, and the fuel injection pump devices.

Secured to the front end of the crank shaft which extends through the front wall of the crank case is a propeller 18.

The cylinders 16 extend radially from the I crank case, and are eachprovided with a flange 19 which engage against the exterior surface of the crank case and are secured by the circular bands 20 which are. laced under tension so that the explosion loads of the 'cylinders are transferred around the crank case. A head 21 is formed integral'with each of the cylinders and an auxiliary head 22 is superposed thereon, a Venturi passage 23 is provided through each of such sets of heads and extends tangentially of the associated c 1i der and at an angle tothe axis thereof. giic passages provide both the inlet and the exhaust ports and air. drawn therethrough for the fuel charge is directed in a manner such that it will rotate upon-entrance'into the cylinder. Avalve 24 is arranged to control the inner end of each of the passages and is held open by the rock lever 25 which is actuated through mechanism extending into the compartment 13 through the housing 26 and be- 191g normally closed by a plurality of springs 2 x It will be understood that the engine illustrated is of the four-cycle Diesel type, and the valve mechanism is arranged so that the passages 23 are open during the exhaust and air intake strokes of the cycle and closed dur ing the compression and explosion strokes of the cycle. A fuel injection device is associated preferably with each of the cylinders and consists of a. nozzle portion 28 and a pump portion 29, the pump being actuated by mechanism arranged within the housings 30 and extending into the compartment 13 where it is operated by suitable mechanism driven from the crank shaft (not shown). A conduit 31 interconnects the several fuel pumps and is connected with a suitable source of supply so that oil will be moved to the pumps under a low pressure while an overflow conduit 32 is associated with the uppermost pump device for returning excess fuel oil in the manifold back to the source of supply.

A connecting rod assembly is associated with the crank pin 33 and consists of a hub portion 34 and a connecting rod 35. Rods 36 are pivotally connected to the master rod hub, in a circular relation, by the pins 37, the rods 36 and the master rod 35 extending into the cylinders and being pivotally connected to pistons 38 arranged to reciprocate therein. The structure so far described is shown and described in detail in my application, Serial No. 358,899, filed April 29, 1929, and reference may be had thereto for a better understanding of the details and operation of the engine shown and described herein.

Starting of an engine of this character is} difficult because combustion occurs .through the heat developed by compression, and furthermore, because the engine 0 crates at a compression of approximately ve hundred pounds per square inch. The cyllnders 111 which the combustion takes place are relatively cold with respect to the combustion temperature, and when the atmospheric temperature is low it is diflicult to obtain suiticient heat by compressing the air drawn into the cylinders to cause combustion. ThlS same condition is also true during idling when some of the cylinders miss, and particularly is this true when the engine is employed as the-power plant of an airplane when flying. in low temperature condltions.

In order to assist starting and the bringing inrof missing cylinders in an engine of this character, I propose to provide a compres'sion ratio regulating mechanism whlch 1s actuated by the pressure lubricating system of the engine and' 'automatically controlled by centrifugal force in a manner such that the compression ratio. will be Tvaried inversely with the speed of rotation of the crank shaft. To this end I provide an eccentric bearing sleeve 40 intermediate the crank pin 33 and the master rod hub 34 and integral with such bearing at one end thereof is an arm 41 extending transversely on opposite sides of the crank check 42. I secure cylindrical housings 43 in which are arranged plun ers 44 and 44' which are pivotally connected y rods 45 with the ends of the arm 41. In order to control the position of the plungers 44 in the cylinders and thereby regulate the relation of the eccentric bearing upon the crank pin, I provide duct means preferably in the arm 42 of the crank shaft which are connected with the pressure lubricating system of the engine and controlled by valve means operated automatically by centrifugal force.

In the compartment 11 there is a pump housing 46 within which there is a gear pump 47 arranged to draw lubricating oil= from the compartment through the conduit 48 and to force the same through the conduit 49, the ducts 50 in the crank shaft and the duct 51 which leads from the crank pin duct into the arm 42. Another gear pump 52 is arranged within the pump housing 46 and draws the lubricantfrom the sump in the compartment 12 through the duct 53 and returns it to the compartment 11 through the duct 54.

The crank arm 42 is provided with a centralaperture 55 in which the valve 56 is slidably mounted. Ducts 57 and 58 connect the inlet duct 51 with the central aperture 55, v

and a duct 59 extends from the end of one of the cylinders and through the crank arm 42 and joins the central passage 55 in the same plane withthe duct 58, while a duct 58 leads fromthe duct 59 to the central passage 55.

A duct 60 extends into the end of the other cylindrical housing and projects lengthwise of the crank arm 42 and terminates in two transversely extending ducts 61 and 62, the duct 61 being in alignment with the duct 57. A duct 63 extends from the central passage 55 through the crank arm into communication with the compartment 12, and another out-let duct 64 extends from the central passage 55 throngh the crank arm and communicates with the compartment 12. The valve tained the speed of approximately 1200 R. P. M., which is the speed required of the engine illustrated to propel an airplane.

When the valve 56 is in the position shown in Fig. 1, the engine is running below 1200 R. P. M., and when in such position the eccentric bearing sleeve is related with the crank shaft so that the connecting rod structure will operate to pro-duce the highest compression ratio within its range of adjustment, and during idling ofthe engine and starting it is desirable that the compression ratio be highest in order to assist combustion. After the engine attains a speed of morethan 1200 R. P. M. then the valve moves toward the retainer 66 and changes the duct arrangement so that the position of the plungers will be changed in a direction to move the cocentric bearing to decrease the compression ratio for operating conditions.

Lubricant is drawn from the compartment 11 and moved through the passages in the crank shaft and into the duct 51 in the crank shaft arm. When the valve is in the position shown in Fig. 1, which does not change under 1200 R. P. M., the valveblocks communication between the ducts 57 and 61 while it establishes communication between the duct 60 and the outlet duct 63 through the groove nearest the crank pin, and at the same time communication is established between the ducts 59 and 58 by the other groove in the valve member. It will be seen that when this valve element is in such position the plunger is maintained at the end of its cylinder because the cylinder is open to the pressure lubricating system and the other cylinder is open to the compartment 12, and the eccentric hearing will thus be maintained in a position causing a high compression ratio. When the valve is moved toward the retainer 66 by centrifugal force, it blocks communication between the ducts 60 and 63, and the ducts 58 and 59 while communication 'is established between ducts 57 and 61 and between the ducts 58' and 64:. Under such circumstances the lubricant flows into the cylinder housing the plunger 44 while the lubricant moves from the other cylinder to the compartment 12. It will be understood that the valve will automatically regulate the plunger positions within their range of movement by determining the quantity of lubricant in the cylinder housings 43, and the arms 45 connect the plungers with the arm 41 so that the position of the bearing is responsive to the plunger positions.

In the duct 51, I provide a ball check valve 7 0 in order to prevent lubricant return from the compression ratio regulating mechanism to the crank pin, which flow could result with thin oil when starting the engine.

The compression ratioregulating mechanism automatically changes the stroke range of the pistons, and therefore the quantity of air drawn into the cylinders will vary inversely with the compression ratio. Consequently a smaller quantity of air is compressed with high compression ratio than with low com.- pression ratio.

The compression ratio device described is compactly associated with the engine so that no substantially additional space is required for its reception. The device increases the compression ratio when the engine is idling or receiving small fuel charges and consequently is very useful for starting and bringing in missing cylinders under such conditions.

While a specific embodiment of the invention hasbeen herein described, which is deemed to be new and advantageous and may be specifically claimed, it is not to be understood that the invention is limited to the eX- act details of the construction, as it will be apparent that changes may be made therein without departing from the spirit or scope of the invention.

What I claim is: e

1. In an internal combustion engine, a pressure lubricating system, mechanism controlled by the lubricating system regulating the engine compression ratio, and valve means actuated by centrifugal force associated to automatically control the application of the lubricating system to control the mechanism.

2. In an internal combustion engine, a pressure lubricating system, mechanism controlled by the apphcation of the lubricating system thereto to 'regulate the engine compression ratio, and valve means automatically movable in response to centrifugal force to control the application of the lubricating system to the mechanism to vary the compression ratio inversely to the engine speed.

3. In a radial internal combustion engine, the combination with a crank shaft. a connecting rod assembly including a master rod, and a pressure lubricating system, of compression ratio regulating mechanism comprising an eccentric bearing sleeve intermediate the crank shaft and the hub of the master rod, mechanism controlling the bearing sleeve position on the shaft, said lubricating system being associated with said mechanism and means automatically regulating the application of the lubricating sys-, tem to the mechanism controlling the sleeve.

4. In a radial internal combustion engine, the combination with a crank shaft, a connecting rod assembly including a master rod. and a pressure lubricating system, of compression ratio regulating mechanism variable inversely with the engine speed comprising an eccentric bearing sleeve intermediate the crank shaft and the hub of the master rod. mechanism for regulating the position of the sleeve relative to the crank shaft controlled by the-pressure lubricating system, and centrifugally actuated means for controlling the application of the lubricating system to said mechanism.

5. In a radial internal combustion engine, the combination with a crank shaft, a connecting rod assembly including a master rod, and a pressure lubricating system, of compression ratio regulating mechanism comprising an eccentric bearing sleeve intermediate the crank shaft and the hub of the master rod, spaced housings secured to the crank shaft, plungers inthe housings connected to the sleeve, said crank shaft having ducts therein for conducting lubricant from the'system to the housings and from the housings, and means for controlling the ducts to control the position of the pistons in the housings.

6. In a radial internal combustion'engine, the combination with a crank shaft, a connecting rod assembly including a master rod, and a pressure lubricating system, of compression ratio regulating mechanism comprising an eccentric bearing sleeve intermediate the crank shaft and the hub of the master rod, said bearing sleeve having a transversely extending arm, a pair of spaced housings fixed to the crank shaft, plungers in the housin s, connections between the plungers and the earing sleeve arm, means for connecting the lubricating system with the housings, and a centrifugally actuated valve for controlling the flow of lubricant to and from the housings.

7. In a radial internal combustion engine, the combination with a crank shaft, a' connecting rod assembly including a master rod, and a pressure lubricating system, of compression ratio regulating mechanism comprising an eccentric bearing sleeve' intermediate the crank shaft and the hub of the master rod, a pair of spaced housings fixed to an arm of the crank shaft, plungers in the housings connected to the sleeve, said crank shaft arm having duct means connecting the lubricating system with the housings and for conducting lubricant from the housings, and a valve member in the crank shaft arm responsive to centrifugal force to control the flow of lubricant to and from the housings.

8. In a radial internal combustion engine, the combination with a crank shaft, a connecting rod assembly including a master rod, and a pressure lubricating system, of compression ratio regulating mechanism comprising an eccentric bearing sleeve interinediate the crank shaft and the hub of the master rod, a pair of spaced housings fixed to the crank shaft, plungers in the housings connected to the eccentric sleeve, duct means leading from the lubricating system to the housings and from the housings, a valve operated by centrifugal force controlling the flow of lubricant to and from the housings, and means resislting the effect of centrifugal force upon'the va ve.

9. In a radial internal combustion engine, the combination with a crank shaft, a connecting rod assembly including a master rod, and

a pressure lubricating system, of compression ratio regulating mechanismcomprising an eccentric earing sleeve intermediate the crank shaft and the hub of the master rod, a pair of spaced housings fixed to the crank shaft,

plungers in the housings connected to the eccentric sleeve, duct means leading from the lubricating system to the housings and from the housings, a valve operated by centrifugal force controlling the flow of lubricant to and from the housings, and a spring exerting pressure against the valve.

' 10. In a radial internal combustion engine, the combination with a crank shaft, a connect-,,' ing rod assembly including a master rod, and a pressure lubricating system, of compression ratio regulating mechanism comprising an eccentric bearing sleeve intermediate the crank shaft and the hub of'the master rod, an arm fixed to the sleeve, a pair of housings fixed to the crank shaft, plungers in'the housings, rods pivotally connecting the plungers with the sleeve arm, duct means leading from the lubricating system to the housings and from the housings, a centrifugally actuated valve regulating the lubricant flow'to and from the housings to regulate the mechanism and cause a variable compression ratio inversely .to the,

engine speed, and a spring exerting pressur" against the valve normally maintaining a high compression ratio.

11. In an internal combustion engine, a source of hydraulic pressure, mechanism controlled by the hydraulic pressure, regulating the compression ratio, and means responsive to the'engine crank shaft speed for cdntrolling the application of the pressure to the mechanism to cause compression ratio which varies inversely with such speed.

12. In an internal combustion engine, a crank shaft, a pressure lubricating system in the crank shaft, an eccentric piston rod bearing mounted on the crank shaft, mechanism carried by the crank shaft and associated with the bearing to regulate its position angularly on the crank shaft, said mechanism bein connected to be actuated by the pressure lu ricating system, and valve means regulating the connections of the lubricating system with the mechanism, said valve means being automatically adjustable in response to centrifugal force.

13. In an internal combustion engine, a fluid pressure system, compress on ratio changing mechanism connected to be actuated by the pressure system, and valve means controlling the flow of fluid from the system to the mechanism, ,said valve means being automatically adjustable in response to centrifugal force.

14. In an internal combustion engine, a flu d pressure system, compression ratio changing mechanism connected to be regulated by the fluid pressure in the system, valve means controlling the application of the fluid pressure to the mechanism, said valve means being adjustable in response to centrifugal force, and spring means engaging the valve means, said spring means opposing the movement of the valve means by centrifugal force.

15. In an internal combustion engine, a crank shaft having a pressure lubricating system therein, an eccentric piston rod bearing on the shaft, mechanism connected to rotate and maintain the bearing position angularly on the crank shaft, fluid connection means between the system and the mechanism, said connection means and said mechanism rotating with the crank shaft,

valve means in the connection means movable in response to a predetermined centrifugal force, and a spring opposing the movement of the valve means, said valve means normally being positioned to permit fluid flowmaintaining the mechanism in a low compression ratio relation and being adjustable only under a predetermined centrifugal force to lower the compression ratio. In testimony whereof I affix my signature.

HERBERT C. EDWARDS. 

